Hydraulic forging press



1968 HANS-JOACHIM PAHNKE 3,397,568

HYDRAULI C FORG ING PRES 5 Filed Aug. 23, 1966 NVENTOR Hem 1W?" BY rudaddfi ATTORNEY United States Patent Rath, Germany Filed Aug. 23, 1966, Ser. No. 574,420 Claims priority, applicatitgr gegmany, Aug. 25, 1965,

Claims. 61. 72-453 The present invention relates to hydraulic forging presses in general, and more particularly to improvements in forging presses of the cast steel frame type. Still more particularly, the invention relates to forging presses whose frames comprise two columns extending between upper and lower crossheads.

An important requirement in a modern under drive or top drive forging press is that its frame should withstand bending and other stresses which develop when the press is in actual use. This insures that each of a series of successive blanks undergoes identical deformation. Rigidity of the frame is of particular importance when the press is controlled by an automatic programming system which causes its movable parts to reverse the direction of their movement without delay when such parts reach the one or the other end position. The inertia of moving parts subjects the frame to extremely high stresses which are particularly felt in regions where the columns are connected with the crossheads. The rigidity of four-column frames is more satisfactory; however, forging presses using four-column frames are not as readily accessible so that the introduction and withdrawal of blanks, die blocks and other auxiliary equipment presents many problems. Also, the forging operation cannot be observed as freely as in a forging press with a twocolumn frame. A drawback of many presently known two-column frames for forging presses is that the columns tend to flex transversely of the general plane of the frame when the workpiece undergoes deformation, and the attempts to improve the stability of such columns by utilizing therefor profiled U-shaped stock have met with limited success, especially in heavy-duty forging presses.

Accordingly, it is an important object of the present invention to provide a forging press, particularly an under drive forging press of the cast steel two column frame type, wherein the frame can more readily withstand all su-ch stresses which arise in actual use and wherein the frame may be precision finished with reduced expenditures in time and machinery.

Another object of the invention is to provide a novel one-piece cast steel two-column frame for use in a hydraulic forging press.

A further object of the invention is to provide a hydraulic under drive forging press with a cast steel twocolumn frame which can withstand higher flexing and similar stresses than presently known two-column frames.

An additional object of the invention is to provide a hydraulic forging press of the just outlined characteristics wherein the frame reciprocates with reference to a floorsupported traverse or anvil which carries one of the die blocks and wherein such traverse can be made sturdier, larger and simpler than in heretofore known underground forging presses.

A concomitant object of the invention is to provide an improved hydraulic forging press of the type wherein the inclination of the main forging axis with respect to the general plane of the two-column frame may be varied, wherein all stages of the forging operation may be observed in full detail, and which provides ample room for admission, shifting or withdrawal of workpieces as well as for introduction and retraction of auxiliary equipment.

Still another object of the invention is to provide a 3,397,568 Patented Aug. 20, 1968 "ice very simple and sturdy system of guide means for the columns of a one-piece cast steel two-column frame in an under drive hydraulic forging press.

Briefly stated, my invention resides in the provision of a hydraulic forging press which comprises a preferably rectangular floor-mounted anvil or traverse and a boxshaped one-piece cast steel frame disposed in a vertical plane and comprising upper and lower crossheads and spaced columns extending between such crossheads at the opposite sides of the traverse. The cross section of each column resembles a rectangle bounded by two longer and two shorter sides with the former extending transversely of the general plane of the frame and preferably at right angles to the shorter sides. In accordance with a feature of my invention, the width of the traverse equals the distance between the adjoining inner surfaces of the columns and this traverse is provided with two integral brackets or guide members which extend beyond its upper side and underside and cooperate with U-shaped complementary guide members to define therewith two vertical channels for the columns of the one-piece frame. The U-shaped guide members are preferably bolted or otherwise mechanically connected with the brackets.

The reciprocating means for effecting relative movement between the traverse and the frame comprises one or more hydraulic cylinder and piston units operating between the traverse and one of the crossheads. For example, and if the press is of the under drive type wherein the lower half of the frame extends into a pit below the traverse, the cylinder may be anchored in the traverse and the piston or ram of the reciprocating means is fixed to the lower crosshead. The traverse and the upper crosshead then support suitable die blocks for the workpieces which are preferably admitted in a direction making an acute angle with the general plane of the frame. This allows for observation of the forging operation and provides ample room for introduction and withdrawal of auxiliary equipment.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved hydraulic forging press itself, however, both as to its construction and the mode of assembling and operating the same, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of a specific embodiment with reference to the accompanying drawings, in which:

FIG. 1 is a side elevational view of the forging press, with a portion of the guide sleeve for one of the columns broken away and with the supports for the traverse omitted;

FIG. 2 is a transverse vertical section as seen in the direction of arrows from the line IIII of FIG. 1; and

FIG. 3 is a horizontal section as seen in the direction of arrows from the line III-III of FIG. 2.

Referring to the drawings in detail, there is shown an underdrive hydraulic forging press which comprises a floor-supported traverse or anvil 6 and. a box-shaped frame 1 constituted by a one-piece casting and disposed in a vertical plane. The frame comprises upper and lower crossheads 2, 3 and two spaced upright columns 4 and resembles a chain link with gradual and smooth transitions between the reinforced end portions 40 of the columns 4 and the respective end portions of the crossheads. As shown in FIG. 3, the cross section of each column 4 resembles a rectangle whose longer sides extend transversely of the general plane of the frame 1 and are normal to the shorter sides. The ratio of the length of longer sides to the length of shorter sides is preferably two-to-one. The end portions 4a of the columns 4 are bounded by smooth concave internal surfaces 4A, and the inner and outer surfaces 3 4B, 4C of the columns are smooth all the way from end to end.

The width of the traverse 6 equals the distance between the columns 4, and this traverse comprises integral castings in the form of guide members or brackets 7 which are connected with complementary U-shaped guide members 8 to form therewith two vertical sleeves defining channels each of which receives one of the columns 4. The fastener means connecting the brackets 7 with the respective U-shaped guide members 8 comprises bolts 10. The outer faces of the brackets 7 are formed with vertically extending grooves 7a which receive complementary tongues 11 provided on the adjoining faces of the respective guide members 8. The guide members 7 are located entirely within the outline of the main body portion of the traverse 6.

The reciprocating means for moving the frame 1 up and down comprises a double-acting cylinder and piston unit whose cylinder 12 is anchored in the traverse 6 and receives a piston or ram 13 which is attached to the lower crosshead 3.

The top face of the traverse 6 carries a table 14 for a lower die block 15. The upper die block 16 is secured to the upper crosshead 2. The direction in which the workpieces or blanks are being fed into the space between the die blocks 15, 16 is indicated in FIG. 3 by a line 17-18 which extends substantially diagonally of the traverse 6 and rpresents the main forging axis of the press. This axis makes with the central symmetry plane of the frame 1 an acute angle alpha. The line 19-20 is normal to the line 17-18 and indicates the direction in which the die blocks 15, 16 and other auxiliary equipment may be moved into and from operative position.

The numerals 9 denote in FIG. 2 adjustable guide strips or wedges which are inserted between the surfaces of the column 4 and the adjoining faces of the guide members 7, 8. The manner in'which such wedges are adjustable is well known in the art and forms no part of the present invention.

The traverse 6 preferably resembles a body of rectangular outline and its width 21 between the inner surfaces of the columns 4 is sufficient to guarantee requisite stability of the frame. The underside of the traverse 6 rests loosely on profiled supporting beams 5. The side faces 6A of the traverse 6 are normal to the plane of the frame 1.

The sleeves including guide members 7 and 8 insure that the frame 1 is properly guided during engagement of die blocks 15, 16 with the workpieces. The rigidity of the frame is enhanced due to rectangular cross-sectional shape of the columns 4 whose moment of resistance is very high, particularly in the diagonal direction. Furthermore, and since the longer sides of the rectangular cross sections of the columns 4 extend at right angles to the general plane of the frame, the latter offers very high resistance to flexing to the right or to the left, as viewed in FIG. 2. This is of particular importance because the main forging axis 17-18 is not normal to the plane of the frame. The brackets 7 of the traverse 6 are rigid because there is ample room for their material since the columns 4 are located at a considerable distance from each other. As shown in FIG. 1, the thickness of the brackets preferably increases in directions from their upper and lower ends toward the rnain body portion of the traverse 6 so that such brackets offer very high resistance to deformation and guarantee accurate guidance of the frame. Since the brackets 7 do not extend beyond the outline of the main body portion of the traverse 6, the latter may be conveniently introduced into and withdrawn from the space between the columns 4 by moving in directions at right angles to the general plane of the frame 1.

The upper reinforced end portions 40 of the columns 4 can begin at a level directly above the brackets 7 when the frame 1 is moved to its lower end position, and the same holds true for the lower end portions 4a which can extend to a level directly below the brackets 7 when the frame is moved to upper end position. The concave inner surfaces 4A of the reinforced end portions 4a can be treated by a large milling cutter or the like. The end portions of the surfaces 4A preferably resemble parts of cylindrical surfaces.

The above-described forging press may be utilized with advantage in so-called multi-stage drawing operations wherein a blank is deformed in a series of steps and wherein only one-half of the width of die blocks 15, 16 is used at a time. Such mode of operation invariably results in generation of extremely high eccentric stresses which act in the direction of the blank axis and subject the columns to tensional as well as bending or flexing stresses. Flexing of columns results in shifting of die blocks from the center of the press and also in angular displacement of die blocks. Such flexing of columns and its undesirable consequences are fully avoided in the press of the present invention.

The wedges 9 which protect the guide sleeves 7, 8 and columns 4 will be adjusted from time to time to compensate for their wear. These wedges insure that the frame 1 is always guided with a high degree of accuracy and that the sleeves undergo little wear.

In some instances, the columns 4 may be replaced by columns of U-shaped cross section or by columns whose surfaces 48, 4C extend in parallelism with the general plane of the frame.

The die blocks 14, 15 are preferably mounted for swiveling movement about a common vertical axis (the axis of the ram 13) to change the angle alpha. In such forging presses, the surfaces 4B, 4C of the columns 4 can make with the general plane of the frame 1 an angle of 90 minus alpha, wherein alpha is the median value of the angle alpha shown in FIG. 3.

Experiments with my improved frame have shown that it can stand much higher stresses than a frame wherein the columns are bolted or otherwise detachably affixed to the crossheads. Stress concentrations due to so-called notch effect are reduced or do not develop at all. Also, the improved frame is superior to frames with cylindrical columns because the fiat surfaces 4B, 4C of the columns 4 permit for more accurate guidance of the frame with reference to the traverse 6. Accurate guidance of columns is of particular importance in underdrive forging presses wherein the scale accumulates in the pit below the traverse and is more likely to affect the lower portions of the columns.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is:

1. In a hydraulic forging press, a floor-supported traverse; a box-shaped one-piece frame disposed in a vertical plane and comprising spaced upper and lower crossheads and two spaced columns extending between said crossheads at the opposite sides of said traverse, the cross-section of each of said columns resembling a rectangle bounded by pairs of longer and shorter sides and one pair of said sides extending transversely of said vertical plane, the width of said traverse being substantially equal to the distance between said columns and said traverse comprising a pair of integral first guide members each adjacent to one of said columns; a substantially U-shaped second guide member adjacent to each of said first guide members and defining therewith a vertical channel for the respective column; fastener means securing said second guide members to the respective first guide members; and reciprocating means including a cylinder and piston unit operating between said traverse and one of said crossheads for moving the frame with reference to said traverse whereby said columns slide in the respective channels.

2. A structure as set forth in claim 1, wherein each first guide member constitutes a first portion of a vertical sleeve whose second portion is constituted by the respective second guide member, one of said portions having at least one substantially vertical tongue extending into a complementary groove provided in the other portion.

3. A structure as set forth in claim 1, wherein the ratio of the longer sides to the shorter sides of said rectangles is substantially 2:1, wherein said shorter sides make a right angle with said longer sides, and wherein said longer sides make a right angle with said vertical plane.

4. A structure as set forth in claim 1, wherein said columns have reinforced end portions gradually merging into the respective crossheads.

5. A structure as set forth in claim 1, wherein said end portions are bounded by concave internal surfaces.

'6. A structure as set forth in claim 1, wherein said columns have smooth vertical surfaces facing away from the adjoining side faces of said traverse.

7. A structure as set forth in claim 1, wherein said frame resembles a chain link and wherein said cylinder and piston unit operates between said traverse and said lower crosshead.

8. A structure as set forth in claim 1, wherein said traverse is of rectangular outline and comprises two parallel side faces extending at right angles to said vertical plane.

9. A structure as set forth in claim 1, wherein said vertical plane makes an acute angle with the direction in which the workpieces are advanced between said columns at a level above said traverse.

10. A structure as set forth in claim 1, wherein said frame is a one-piece casting and said columns have smooth inner and outer surfaces located in vertical planes making right angles with said first mentioned vertical plane.

References Cited UNITED STATES PATENTS 104,948 7/ 1870 Ferris 72456 113,508 4/ 1871 Ferris 72456 2,869,177 1/ 1959 J urgeleit 72456 3,024,676 3/ 1962 Howahr 72456 3,158,046 11/1964 Steinfort 72453 3,243,988 4/1966 Groos l00214 FOREIGN PATENTS 710,780 6/ 1954 Great Britain.

CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner. 

1. IN A HYDRAULIC FORGING PRESS, A FLOOR-SUPPORTED TRAVERSE; A BOX-SHAPED ONE-PIECE FRAME DISPOSED IN A VERTICAL PLANE AND COMPRISING SPACED UPPER AND LOWER CROSSHEADS AND TWO SPACED COLUMNS EXTENDING BETWEEN SAID CROSSHEADS AT THE OPPOSITE SIDES OF SAID TRAVERSE, THE CROSS-SECTION OF EACH OF SAID COLUMNS RESEMBLING A RECTANGLE BOUNDED BY PAIRS OF LONGER AND SHORTER SIDES AND ONE PAIR OF SAID SIDES EXTENDING TRANSVERSELY OF SAID VERTICAL PLANE, THE WIDTH OF SAID TRAVERSE BEING SUBSTANTIALLY EQUAL TO THE DISTANCE BETWEEN SAID COLUMNS AND SAID TRAVERSE COMPRISING A PAIR OF INTEGRAL FIRST GUIDE MEMBERS EACH ADJACENT TO ONE OF SAID COLUMNS; A SUBSTANTIALLY U-SHAPED SECOND GUIDE MEMBER ADJACENT TO EACH OF SAID FIRST GUIDE MEMBERS AND DEFINING THEREWITH A VERTICAL CHANNEL FOR THE RESPECTIVE COLUMN; FASTENER MEANS SECURING SAID SECOND GUIDE MEMBERS TO THE RESPECTIVE FIRST GUIDE MEMBERS; AND RECIPROCATING MEANS INCLUDING A CYLINDER AND PISTON UNIT OPERATING BETWEEN SAID TRAVERSE AND ONE OF SAID CROSSHEADS FOR MOVING THE FRAME WITH REFERENCE TO SAID TRAVERSE WHEREBY SAID COLUMNS SLIDE IN THE RESPECTIVE CHANNELS. 